Field of the Invention
This invention relates to an electrical installer hand tool. More particularly, the present invention relates to an electrical installer hand tool involving a wire shaping system.
Description of the Related Art
Electrical wires are typically cylindrical in shape, are of indeterminate length, and are encased within an insulating sheath that must be removed before installation. The electrical wire may be a single strand, or may be a plurality of strands twisted in helical fashion to form an approximately cylindrical configuration. These wires are of various diameters, materials, and stiffness. In use, a portion of the insulation, at an end of the wire, is removed, and the bare wire is then formed into a controlled bend of a desired dimension. The controlled bend has an arcuate portion or bight with a relatively straight portion or leg at the end. It is often, but not always, desirable that the legs be parallel, or approximately parallel to a main wire body, for ease of assembly to a contact or terminal connection. It will be understood, that non-parallel bending is also suitable depending upon the particular installation geometry, such that it is sufficient to note the wire must be bent with an arcuate angle to engage a screw. Typically, the contact is a screw having a threaded shaft and a shaped head of substantially larger diameter than the shaft (the shaped head having a geometry for driving (slot, Phillips, square, star drive etc.), the controlled bend being placed so that the two legs straddle the threaded shaft of the screw, and are beneath the head of the screw for electrical connection. After positioning the controlled bend of the wire in this manner, the screw is tightened, so that the underside of the head of the screw engages the electrical wire controlled bend and presses it against another part of the contact structure.
Pliers are typically used to form the controlled bend in an electrical wire with the electrical installer grasping one end portion of a generally straight wire, without insulation on the end portion, and bending the wire to form a controlled bend. Care and skill are required to form the controlled bend in the wire so that the legs are in the desired relation to each other. If the leg at the free end of the wire is not bent far enough, that is, is bent through significantly less than 180 degrees, an open V-shaped bend will result, which provides a structure that might be too large to be positioned in the terminal structure, due to parts providing a limited space for the bent wire.
When this occurs, time is consumed in rebending or unbending the wire with the intent of making the two legs substantially parallel and aligned, but care must be taken to avoid bending the leg forming the free end of the wire too much for, in that event, the leg forming the free end of the wire will substantially close the opening which is used for the straddling of the screw shank by the two legs of the bent wire. Also, if too much force is initially applied to the wires, a closed loop will be formed, prohibiting manipulation of the wire so as to straddle the screw shank in a tight confinement geometry. Electrical installers have used conventional long-nose pliers to form such controlled bends. Round nose pliers have permitted formation of more circular loops, but, because of their tapered jaws, they do not ensure that repeated use will result in identically sized or shaped loops. However, this results in imperfect loops and imperfect connections.
Other specialty pliers are known for bending wires or forming them into loops, commonly known as wire wrapping pliers, which have one jaw formed in a series of stepped diameter cylinders, and the other jaw being flat or concave where it faces the cylindrical jaw. Such wire wrapping pliers are not convenient to forming tight loops because the wire was gripped between the jaws at a location which was typically 180 degrees away from the closure of the loop. Forming the loop adjacent the contact between the jaws of such pliers exposes the wire to the edge of the flat or concave jaw, reintroducing the possibility of undesired deformation of the wire resulting from contact with such edge.
Other wire bending tools include a terminal connector having a disc with a hole through which the shank of a terminal screw is inserted. The disc has a pair of upstanding flanges that are spaced apart. The wire is passed adjacent to the shank of the screw and between the spaced flanges. A screwdriver is then used to rotate the screw to bend the wire around the screw shank. The wire is then placed on a screw forming part of the wire terminal.
These known tools all have the same or similar deficiencies. That is, these tools are not able to form controlled bends in a consistent and conventional manner, and cannot provide a controlled bend in which the legs are substantially parallel, and are not adaptable to deal with the various gauges (thicknesses) of wire. Conventionally, with all of these tools, great care is required by the electrical installer in order to achieve the formation of a bend of optimum configuration for placing on the threaded shank of a terminal screw. Moreover, some of these devices are combined terminal and tool device, and are not a separate, readily usable workman's tool for making controlled bends in wires in preparation for placement of the wires on electrical terminal screws separate from the tool. These conventional tools also prohibit adaption to tight confinement working places (e.g., in a breaker box, etc.), and do not adapt to various wire-bending orientations.
The present invention overcomes at least one of the proposed shortcomings of the prior art by providing a wire shaping, bending or forming device that may be used in conjunction with any number of tools that may be used by electricians and that is easy and convenient to use in order to form precise and consistently-sized wire bends or loops depending on the gauge or size of the wire.